To better understand the status of the Boreal Owl (Aegolius funereus) at the southern extremity of its North American range, we conducted audio playback surveys between late July and mid-October 2012 at seven of the nine northern New Mexico locations where the species had been documented between 1987 and 1993, as well as four additional locations 10-15 km from sites of previous detections. All survey locations were in subalpine conifer forest at elevations >3000 m above sea level. In total, we called in at least 12 individuals (6 adults and 6 juveniles) at or near six of the seven historical locations and at least three adults at two new locations. Of the eight locations with confirmed Boreal Owl detections, two were in the San Juan Mountains, two were in the Jemez Mountains, and four were in the Sangre de Cristo Mountains. Recently fledged owls were seen at both San Juan Mountain sites and photo-documented at one site. Adult owls were photo-documented at the other six locations. Detection of Boreal Owls at six of seven historical locations confirmed the species' long-term residency in New Mexico's three northern mountain ranges. While Boreal Owls have likely been present in New Mexico since the Pleistocene, climate change appears likely to threaten their high-elevation habitat, particularly since more frequent and larger fires are predicted in the future as the forest dries.

Grassland and shrubland birds are declining globally due in part to anthropogenic habitat modification. Because population performance of these species is also influenced by nonanthropogenic factors, it is important to incorporate all relevant ecological drivers into demographic models.We used design-based sampling and occupancy models to test relationships of environmental factors that influence raptor demographics with re-occupancy of breeding territories by ferruginous hawks (Buteo regalis) across Wyoming, USA, 2011-2013. We also tested correlations of territory re-occupancy with oil and gas infrastructure-a leading cause of habitat modification throughout the range of this species of conservation concern. Probability of re-occupancy was not related to any covariates we investigated in 2011, had a strong negative relationship with cover of sagebrush (Artemisia spp.) in 2012, was slightly higher for territories with artificial platforms than other nest substrates in 2013, and had a positive relationship with abundance of ground squirrels (Urocitellus spp.) that was strong in 2012 and weak in 2013. Associations with roads were weak and varied by year, road-type, and scale: in 2012, re-occupancy probability had a weak positive correlation with density of roads not associated with oil and gas fields at the territory-scale; however, in 2013 re-occupancy had a very weak negative correlation with density of oil and gas field roads near nest sites (≥500 m). Although our results indicate re-occupancy of breeding territories by ferruginous hawks was compatible with densities of anthropogenic infrastructure in our study area, the lack of relationships between oil and gas well density and territory re-occupancy may have occurred because pre-treatment data were unavailable. We used probabilistic sampling at a broad spatial extent, methods to account for imperfect detection, and conducted extensive prey sampling; nonetheless, future research using before-aftercontrol-impact designs is needed to fully assess impacts of oil and gas development on ferruginous hawks.